Jurnal Keteknikan Pertanian
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The ratio of specifc heat capacity, at constant presszrre to that at constant volume (cdc,J, of a gas can be determined by either the adiabatic expansion method or the sound velocity method. The objective of this experiment is apply the adiabatic expansion method for determining the spec$c heat capacity ratio of gas N2 and O2 The result showed that the ratio were 1.14 and 1.19 respectively for gas N2 and 02.T he value obtained by the experiment was d~flerenta bout 15 to 19% from the result determined by theoretical method using 5 degree of Jkeedom. Theoretically cdc,, of both gas N2 and 0 2 which have 5 degree offreedom are 1.4. The dzflerence was considered to be caused by thee xperimental condition, which were not suflciently adiabatic, as required by the method. However, the simplicity of the method and clarity of its theoretical approach is advantageous to be used by students of Advance Thermodynamic class as a practical exercise.
No full textThe ratio of specifc heat capacity, at constant presszrre to that at constant volume (cdc,J, of a gas can be determined by either the adiabatic expansion method or the sound velocity method. The objective of this experiment is apply the adiabatic expansion method for determining the spec$c heat capacity ratio of gas N2 and O2 The result showed that the ratio were 1.14 and 1.19 respectively for gas N2 and 02.T he value obtained by the experiment was d~flerenta bout 15 to 19% from the result determined by theoretical method using 5 degree of Jkeedom. Theoretically cdc,, of both gas N2 and 0 2 which have 5 degree offreedom are 1.4. The dzflerence was considered to be caused by thee xperimental condition, which were not suflciently adiabatic, as required by the method. However, the simplicity of the method and clarity of its theoretical approach is advantageous to be used by students of Advance Thermodynamic class as a practical exercise
Optimation of Tank Model\u27s Parameters
No full textTank to model is one of hydrological models to analize characteristics of river flow. The model can give information of water availability and be used to predict flood occurences. As it is setting the embodied parameters. In from of Standard Tank Model, the number of parameters accounts to 12. Many optimation method available for general application. This paper introduces an optimation technique to determine the parameters with taking into account confornity to water balance in addition to best-fifting. Here, two data from Cidanau and Terauchi Watershed were used for clarification, which show that this optimation technique gained fast and accurate result. This technique has been made available to use in form of an application sofware and openly possible to accomodate the other forms of Tank Model
Teknik Rekayasa Pemadatan Kayu II : Sifat Fisik dan Mekanik Kayu Agatis (Agathis lorantifolia Salisb.) Terpadatkan dalam Konstruksi Bangunan Kayu
No full textPemadatan kayu dapat dilakukan dengan dua langkah utama, yaitu perlakuan perendaman, perebusan dan pengukusan agar kayu bersifat plastis dan perlakuan pemadatan pada arah tegak lurus serat. Proses plastisasi dan pemadatan kayu yang sesuai dapat meningkatkan sifat fisik dan sifat mekanik kayu terpadatkan dan berkualitas tinggi. Kualitas yang dimaksud adalah kemudahan proses pemadatan, stabilitas dimensi, keseragaman dan peningkatan kekuatan papan kayu, kehalusan corak permukaan papan dan fiksasi permanen
Particle Size Effect in Model Retaining Wall on Passive Mode with Granular Material
No full textThis paper presented a particle size effect on model retaining wall by comparing the experimental and finite element analysis. The experiments were conducted with air-dried Toyoura sand and Soma sand plane strain condition, both sand are standard sand in Japan. The wall was oved horizontally into sand. The hights of sand mass in these experiments were 5 cm, 10 cm, and 15 cm. The finite element analysis employed a constitutive model in which non-associated strain hardening-softening elasto-plastic materila was employed. This analysis introducted the effect of shear band thickness. The result obtained from the finite element analysis showed a good agrement with the results obtained from the experimental investigation. From both experimental and analytical results, there was evident of particle size effect due to shear banding
Crop Growth and Water Use Modelling of Upload Crops
Get PDFPalawija is still used as secondary food in Indonesia. Some of palawija crops were source of the carbohydrate, and the others like a peanut and soybean are source of protein. The common palawija crops grown on upland area are soybean, peanut, green pea, and corn. The major constrains on development of upland area for agriculture purpose was water scarcity and availability data of crops water requirement. The objective of the research was to develop the crop growth and water use modeling, determining the transpiration coefficient and crop water requirement of upland crops
Simulation of Temperature Control in Growth Room for Tropical Mushroom
No full textOptimum growth of tropical mushrooms depend on the ambient environment. In general, mushrooms prefer low air temperature and high air humidity. The growers use closed rooms to maintain favorable conditions. Recently, use of refrigerator is of interest to maintain the favourable conditions under hot and humid climate conditions. This study is attempting to apply control mechanism in maintaining theambient temperature favorable for mushroom growth. A simple heat transfer equation was used to describe changes of temperature inside the growth chamber. This equation was then coupled with a fuzzy logic control to actuate a refrigerator at a suitable length of time. Three temperature condition (16, 19 and 21 O C ) were set as set points. The results show the developed technique was capable to maintain the temperature inside the growth room even though under the influence of a highly fluctuating ambient temperature. This technique was alsoresponsive and reliable in facing immediate disturbances, and showed a realistic requirement of cooling energy
Freeze drying of food materials is a time and energy consuming process, hence a high cost process. The drying rate is limited by heat and mass transfer process within the dried portion of the product. In order to improve the freeze drying performance, it is important to know parameters which affect the drying characteristics of each spesific food material, in regard to the drying time and the energy consumption. The objective of this experiment was to study the freeze drying characteristic of miched beef especially the effect of freezing rate and surface temperature of the material to the drying time. The study was conducted with freezing rate at 7.71 cmhours and 1.94 cmhours which are classified into fast and slow freezing rate, while the surface temperature of the material was controlled at 40 OC, 35 OC, and 30 OC. The experimental results confirmed that the faster freezing rate then the longest drying time, while the higher surface temperature give a shorter drying time of miched beef. It is important to determine the optimal freezing rate and surface temperature from the view point of energy consumption.
No full textFreeze drying of food materials is a time and energy consuming process, hence a high cost process. The drying rate is limited by heat and mass transfer process within the dried portion of the product. In order to improve the freeze drying performance, it is important to know parameters which affect the drying characteristics of each spesific food material, in regard to the drying time and the energy consumption. The objective of this experiment was to study the freeze drying characteristic of miched beef especially the effect of freezing rate and surface temperature of the material to the drying time. The study was conducted with freezing rate at 7.71 cmhours and 1.94 cmhours which are classified into fast and slow freezing rate, while the surface temperature of the material was controlled at 40 OC, 35 OC, and 30 OC. The experimental results confirmed that the faster freezing rate then the longest drying time, while the higher surface temperature give a shorter drying time of miched beef. It is important to determine the optimal freezing rate and surface temperature from the view point of energy consumption
Fuzzy Control on Artificial Ripening of Uli Banana
No full textBanana is a potential commodity to gain foreign currency since its export has tended to increase yaer by year. Postharvest handling of banana is very important in order to maintain high quality of the products. Artificial ripening is one method applied to control the rate of ripening and in the other side to guarantee the uniformity of quality. Teperature in the ripening chamber plays an important role since it directly influences respiration rate of the products. This research is aimed to apply fuzzy control to regulate the temperature, which is set in order to get better quality of the product. Yhe objective of the fizzy control is to set the temperature into 4 (four) decreasing steps : 1) 24"C. 2)22.5"C 30 21.5 "C and 4) 24 "C each for 24 hours. Respiration rate during these periods are 0.0866 ml CO2/kg/h become 0.06054 ml CO2/kg/h or 3.1716 ml O2/kg/h/ become 0.7016 ml O2/kg/h
This paper concerns with the development of a decision support package for chipper allocation at the transmigration land preparation area. It is intended to be used by chip entrepreneur on determining the most economical chipper allocation and man power requirement. The package was developed by using Turbo Pascal, running well on the computers compatible with ISM PC (XT or AT) with minimum 640 Kb RAM and VGAISuper VGA monitor. Program testing showed that the program has a sufficient capability as a management tool.
No full textThis paper concerns with the development of a decision support package for chipper allocation at the transmigration land preparation area. It is intended to be used by chip entrepreneur on determining the most economical chipper allocation and man power requirement. The package was developed by using Turbo Pascal, running well on the computers compatible with ISM PC (XT or AT) with minimum 640 Kb RAM and VGAISuper VGA monitor. Program testing showed that the program has a sufficient capability as a management tool.
Baru-baru ini Gustav Grob (1996) mengingatkan lagi prediksi Club of Rome di awal tahun 1970-an bahwa bahan bakar fossil, yang sifatnya meneemarkan lingkungan, dan tak terbarukan kian berkurang keberadaannya dan dalam waktu dekat harus diganti dengan sumber energi terbarukan yang lebih bersahabat dengan lingkungan seperti sumber-sumber energi surya, biomassa, angin, hidro, dll. Ketergantungan kita atas bahan bakar fosil mungkin akan berlanjut sampai beberapa dekade lagi tetapi dalam jumlah yang jauh lebih kecil dari apa yang di konsumsikan sebelum tahun 2000 seperti terlihat pada Gambar 1 (Grob, 1996)
No full textBaru-baru ini Gustav Grob (1996) mengingatkan lagi prediksi Club of Rome di awal tahun 1970-an bahwa bahan bakar fossil, yang sifatnya meneemarkan lingkungan, dan tak terbarukan kian berkurang keberadaannya dan dalam waktu dekat harus diganti dengan sumber energi terbarukan yang lebih bersahabat dengan lingkungan seperti sumber-sumber energi surya, biomassa, angin, hidro, dll. Ketergantungan kita atas bahan bakar fosil mungkin akan berlanjut sampai beberapa dekade lagi tetapi dalam jumlah yang jauh lebih kecil dari apa yang di konsumsikan sebelum tahun 2000 seperti terlihat pada Gambar 1 (Grob, 1996)